1. Field of the Invention
This invention relates to reflectors for energy collectors, such as microwave antennas and solar concentrators; and, more particularly, to support systems for the reflector.
2. Prior Art
In a paraboloidal reflector, incoming parallel rays are concentrated upon a focal point in front of a reflective surface. In a Gregorian system the incoming energy is utilized at the focal point. In a Cassegranian system, there is a "double bounce" and the energy from the focal point is reflected back to the center of the reflector. The Cassegranian system may be particularly desirable in situations where the reflector is utilized by relatively bulky components such as microwave horns and it is desired to position these behind the reflector and not suspended at the focal point. In either case, the Gregorian or the Cassegranian, there must be a reflector and an energy utilizing device at the focal point. When conventional rear reflective surface bracing is used, the object at the focal point is often supported by a tripod or quadripod extending from the reflector on relatively long legs. The bracing for these legs and the reflective surface extends around the rear of the reflective surface.
As reflector sizes have increased in size and weight, there has been an attendant increase in the size and weight of the reflector bracing and support structure. The increase in the weight of the reflector support structure produces cost and weight penalties which would be desirable to avoid. For example, in U.S. Pat. No. 2,997,712 issued to D. S. Kennedy there is taught a system for building a sectional reflector support for use behind the reflective surface. Although disassembly of the support structure into sections facilitates transportation, the support structure itself is still undesirably heavy and expensive. Further, the support structure is positioned between the reflective surface and a pivot point to the rear of the reflective surface, thus extending the moment arm from the pivot point to the reflective surface and increasing the torque required to turn the reflective surface.
One variation in reflector surface supports is taught in U.S. Pat. No. 3,558,219 issued to H. E. Buckingham et al. and includes an erectable umbrella-like reflector surface which has a hub with a plurality of hinged radial arms attached at one end of the hub. The arms have rigid segments between which extend a thin flexible reflector membrane. The reflector is supported about an axial rigid member extending through the hub from which extend tension members for supporting the reflective surface. However, this does not solve the problem of a simplified reflector support for a noncollapsable structure with a paraboloidal reflector. These are some of the problems this invention overcomes.